Explanation
the command that should be used to create a new drawing file from selected objects is WBLOCK. This command allows you to export a group of objects as a drawing, which can be inserted into other drawings as a block2.

Explanation
a baseline dimension is a linear, angular, or ordinate dimension that is measured from the baseline of a previous or selected dimension. The spacing between baseline dimensions can be set from the Dimension Style Manager, Lines tab, Baseline Spacing (DIMDLI system variable).
The most efficient method to avoid the problem of dimensions being too close together in the future is to use Dimension Style Manager. This will allow you to change the default spacing for all baseline dimensions in your drawing.
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2015/ENU/AutoCAD

Explanation
UCS is a command that sets a new user coordinate system (UCS) by specifying points or by selecting an object. You can use the Object option to align the UCS with a selected object such as a line.
Based on 3 and 4, UCSBASE is a system variable that sets the name of the current UCS base. PLINEGEN is a system variable that controls how linetype patterns are generated around vertices. LWEIGHT is a command that sets the current lineweight, which is used for new objects and affects objects in the current space only.
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2016/ENU/AutoCAD
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2020/ENU/AutoCAD

Explanation
polyline is a connected sequence of line segments created as a single object that can contain a width. You can change the width of a polyline by using the PEDIT command.
Based on 3 and 4, LWEIGHT is a command that sets the current lineweight, which is used for new objects and affects objects in the current space only. PLINEWID is a system variable that sets a default polyline width for new polylines. PLINEGEN is a system variable that controls how linetype patterns are generated around vertices.
https://www.roadlesstraveledstore.com/how-do-i-change-the-width-of-a-polyline-in-autocad/
https://knowledgeburrow.com/how-do-i-change-the-width-of-a-polyline-in-autocad/

Explanation
True
1. According to the AutoCAD for Design and Drafting documents1, a polyline is a connected sequence of line segments created as a single object. You can create straight line segments, arc segments, or a combination of the two2341. Therefore, the correct answer is True. A polyline can include both straight line segments and arc segments.
2. False.According to the AutoCAD for Design and Drafting documents1, a spline is a smooth curve that passes through or near a set of fit points, or that is defined by the vertices in a control frame. A spline does not have a constant radius, but rather a local radius at each point on the curve2. Therefore, AutoCAD cannot directly dimension or display a radius of a spline curve23. You can use some workarounds such as exploding the curve to arc segments with the FLATTEN command2, or creating a polyline over the top with arc active3, but these may not be accurate or desirable. Therefore, the correct answer is False. The radius on a spline cannot be found in AutoCAD properties.3. TrueAccording to the AutoCAD for Design and Drafting documents1, a 2D polyline is a connected sequence of line segments created as a single object. You can specify an elevation for a 2D polyline using the Edit Polyline Elevations command2. However, this command will assign the same elevation to all vertices of the polyline2. Therefore, you cannot assign different elevations to different segments or points of a 2D polyline. Therefore, the correct answer is True. You can assign only one elevation to a 2D polyline.