Answer: A. 2748
Step-by-step explanation: From the explicit formula: an= a1 + (n -1).d
an means number of terms we are looking for.
a1 means the first term of the arithmetic progression which is 57
d means common differences between the terms. I.e second term (a2)- first term(a1). 66-57=9
Substituting the values into the formulae.
a300= 57 +(300-1)9
a300= 57 +(299×9)
= 57 + 2691
a300 = 2748