When all the angles of system is equal to 90°, i.e. α = β = γ = 90° but the sides are not equal the system is said to be?

When all the angles of system is equal to 90°, i.e. α = β = γ = 90

1.	When all the angles of system is equal to 90°, i.e. α = β = γ = 90° but the sides are not equal the system is said to be?
A.	Orthorhombic
B.	Cubic
C.	Tetragonal
D.	Trigonal
Answer» D. Trigonal