Which two techniques should the developer implement to avoid low performance queries from executing?

In a previous data audit, It was determined that close to 5 million Opportunity records are stored within the Salesforce environment. The organization-wide default for the object are set to Public Read-Only and most opportunities are related to an external case.

The method is called from a Lightning web component. Some end users do not provide a cased value and experience low performance while running the query.

Which two techniques should the developer implement to avoid low performance queries from executing? Choose 2 answers
A . Implement a LIMIT clause within the SOQL query to restrict the result set.
B. Ensure the user-provided input is not null before executing the SOQL query.
C. Implement the with sharing keyword on the Apex class.
D. Use SOSL instead of SOQL queries to perform text-based searches.

Answer: A,D