Options A and C are correct. Both options use the SUBSTR function to extract the first 10 characters of the 'customer _ name' variable and assign it to a new variable named 'short_name'. While option C explicitly defines the length of 'short_name' to 10 bytes, it is unnecessary because the SUBSTR function will automatically truncate the extracted string to 10 characters_ Option B is incorrect because it assigns the entire 'customer_name' variable to 'short_name', not just the first 10 characters, and the LENGTH statement will not truncate the variable. Option D is incorrect because it defines the length of 'short_name' after the variable is already assigned, so it will not affect the length of the assigned value. Option E is incorrect because it uses a length specification within the assignment statement, which is not valid syntax. The LENGTH statement should be used separately. Therefore, the correct code snippets are.

The correct code snippet is option D. The 'keep:' option in the 'set' statement specifies which variables to include in the new dataset, and the option limits the number of observations read from the original dataset to the first 100. Option A incorrectly uses the 'obs=' option in the 'keep=' statement, which is not valid syntax. Option B incorrectly uses the option to remove unnecessary variables and the 'output' statement is redundant. Option C correctly limits the observations but does not specify the number of observations to read. Option E incorrectly uses the 'drop=' option to remove unnecessary variables.

The correct code uses the 'intck' function to calculate the difference in days between the start date and a reference date ('01JAN1960'd). Option D correctly converts the 'START_DATE' variable to a SAS date value using "input(START DATE, yymmdd10.)' before applying 'intck'- Option A is incorrect because it calculates the days from '01 JANI 960'd to 'START_DATE', which is not what the problem requires. Option B uses an incorrect order of arguments for 'intck'- Option C uses 'OIJANI 960'd as a date value, but it doesn't convert 'START DATE' to a SAS date. Option E uses today(), which gives the current date, not a fixed reference date.

The correct answer is ''E''. To format a SAS date value, you need to use the 'input' function to convert the numeric value to a SAS date and then apply the desired format using the 'format' statement. Option E uses the ' input' function with the 'DATE9.' format to convert the numeric value to a SAS date and then applies the 'MMDDYYIO.S format to display the date in the desired format. Option A would only apply the format to the variable but would not convert the numeric value to a date. Option B tries to use the 'put' function, which is used to convert a SAS date to a character string, but does not convert the numeric value to a date first. Option C uses the 'date' function, which expects a string representation of the date and does not work with numeric date values. Option D uses the 'input' function but with the wrong format, which would result in an incorrect date conversion.

Option E is the correct code snippet that achieves the desired formatting. It utilizes the FORMAT statement within a data step to apply different formats based on the 'SalesValue'. For 'SalesValue' less than 100, the '$10.2' format is applied, displaying the value with a dollar sign prefix and two decimal places. For values between 100 and 1000, the '$10. IK' format is used, adding a 'K suffix and one decimal place. Finally, for values exceeding 1000, the '$10.0M' format applies, adding an 'M' suffix and no decimal places. This solution effectively uses the FORMAT statement to achieve the required conditional formatting.