When you use PEMDAS, this would be very easy. Just the others:
Parenthesis(no parenthesis in this expression, so it should be crossed out.)
Exponents (no exponents in this expression, so it should be crossed out)
Multiplication (Yes)
Division (no division in this expression, so it should be crossed out.)
Addition (Yes.)
Subtraction (no subtraction in this expression, so it should be crossed out)
Therefore,
4 + 2 • 8
4 + 16
= 20.
Answer is C) 20.