What should a developer use to query all Account fields for the Acme account in their sandbox?

An org has an existing process, built using Process Builder, on Opportunity that sets a custom field, commissionBaseAmount_ c, when an Opportunity is edited and the Opportunity's Amount changes.
A developer recently deployed an Opportunity before update trigger that use the commissionBaseAmount_ c, andcomplex logic to calculate a value for a custom field, CommissionAmount_ c, when an Opporunity stage changes to Closed/Won.
Users report that when they change the Opportunity stage changes to Closed/Won and also change the Amount during the same save, the commission_ c is incorrect.
Which action should the developer take to correct this problem?

As part of a new integration, a developer is asked to implement a new custom search functional that is capable of performing unrestricted Queries and can account for all values within a custom picklist field. Type_ c, on the Opportunity object. The search feature must also account for NULL values.
The organization-wide default for the Opportunity object is set to Public Read-Only, and a new custom index has been created for the type_ c, field. There are more than 5 million Opportunity records within the environment, and a considerable amount of the existing records have NULL values for the picklist.
Which technique should the developer implement to maximize performance when querying NULL values?

A developer implemented a custom data table in a Lightning web component with filter functionality.
However, users are submitted support tickets about long load times when the filters are changed. The component uses an Apex method that is called to query for records the selected filters.
What should the developer do to improve performance of the component?

Consider the following code snippet:

Which governor limit is likely to be exceeded when the trigger runs when a scope of 200 newly inserted accounts?