what is the length of the diagonal for the given rectangular prism to the nearest whole unit

Length: 8 cm
Width: 3 cm
Height: 7 cm

A. 10 cm
B. 11 cm
C. 6 cm
D.13 cm

please help I cant figure it out

2 answers

B. 11 cm
the length is √(8^2 + 3^2 + 7^2) = √122