For a question like this, order of operations must be followed. This can be expressed with PEMDAS.
P arenthesis
E xponents
M ultiplication
D ivision
A ddition
S ubtraction
8^2 ÷ 4 + 3.7(42.3-24.6) -------> Parenthesis first
8^2 ÷ 4 + 3.7(17.7) ------> Now exponents
64 ÷ 4 + 3.7(17.7) ------> Now multiplication and division
16 + 65.49 --------> And finally addition
81.49 which is answer choice C
I hope this helps!
