A Couple with Three Girls Is Expecting a Fourth Child $\frac { 1 } { 8 }$

A couple with three girls is expecting a fourth child.The probability that this child is also a girl is

A) $\frac { 1 } { 8 }$

B) $\frac { 1 } { 4 }$

C) $-\frac { 1 } { 8 }$

D) $\frac { 1 } { 16 }$

E) $\frac { 1 } { 32 }$