What are the differences between "step$-$over" and "step$-$into" debugging techniques?

Question $3$ options:

a$.$ "Step$-$over" executes one instruction and then moves to the next call instruction, while "step$-$into" completes the call and returns without pausing.

b$.$ "Step$-$over" moves into the function and stops at its first command, while "step$-$into" executes one instruction and then moves to the next call instruction.

c$.$ "Step$-$over" decreases the amount of code you need to analyze by completing the call and returning without pausing, while "step$-$into" might miss important functionality, especially if the function never returns.

d$.$ "Step$-$over" executes one instruction and then moves to the next line of code, while "step$-$into" moves into the function and stops at its first command.