Answer:
B) a = 3, b = 3 .
Step-by-step explanation:
Given :  =
 =  .
.
To find : Which values of a and b make the equation true.
Solution : We have given that  =
 =  .
.
By exponential  same base rule : if base are same then power will be add.
 if base are same then power will be add.
 =
 =  .
.
Solving exponent 
16 =
 =   .
.
On equating x variable 
 =
 =   .
.
By exponent rule : if  =
 =   then m =n.
 then m =n.
So, 4 = a+1 
On subtracting by 1 both sides 
a = 3.
On equating y variable ,
 4 = b+1 
On subtracting by 1 both sides 
b = 3 .
Therefore, B) a = 3, b = 3 .