ABC has
A as the first letter
B as the second letter
C as the third letter
The order is important
Similarly with EFG we hae
E as the first letter
F as the second letter
G as the third letter
The order is also important
Based on the orderings, we can say
A corresponds to E
B corresponds to F
C corresponds to G
Which means
A rotates to E
B rotates to F
C rotates to G
The final answer is choice C) Angle C
since we're looking for the angle that rotates or maps to angle G