Gena wants to estimate the quotient of –21.87 divided by 4.79. Which expression shows the best expression to estimate the quotient using front-end estimation?

You haven't shared the list of expressions from which you are to choose an answer.

However:  you can perform this estimation yourself as follows:

Round off both -21.87 and 4.79.  -21.87 goes to -22 and 4.79 to 5.  Then
a good estimate of -21.87 divided by 4.79 would be -22/5, or -4.4.