Jeremy determines that √9= 9^1/2. Part of his work is shown

√9=3=3^1=3^1/2 + ^1/2=____=9^1/2

Which expression or equation should be placed in the blank to correctly complete Jeremy's work?

A: (3^2)^1
B: 3^1/2 + 3^1/2
C: 3^1/2 x 3^1/2= (3x3)^1/2
D: 3^1/2 x 3^1/2= (3x3)^1/2+^1/2