Explanation:
it is simple - there is a rule you have to burn into your memory for life (together with Pythagoras) :
the sum of all angles in a triangle is always (truly always) 180°.
so,
180 = 79 + (x + 48) + (x + 65)
180 = 79 + x + 48 + x + 65 = 2x + 192
-12 = 2x
x = -6
that means
A = x + 48 = -6 + 48 = 42°
so, the first answer option is correct.
the other angle is x + 65 = -6 + 65 = 59°
and to check
79 + 59 + 42 = 180°
all ok.