When executing SOQL queries, which three options prevent a query from being selective?

Universal Containers has a custom object with millions of rows of data.

When executing SOQL queries, which three options prevent a query from being selective? (Choose three.)
A . Utilizing NOT and != operators.
B . Utilizing a custom index on a deterministic formula field.
C . Using leading % wildcards.
D . Performing large loads and deletions.
E . Using trailing % wildcards.

Answer: BCE