In tetragonal crystal system, which of the following is true?

In a tetragonal crystal system, the unit cell has three axes, a, b, and c. The lengths of the a and b axes are equal (a = b), but the length of the c axis is different (c ≠ a ≠ b). All axial angles (α, β, γ) are equal to 90°. Therefore, the correct statement is that two axial angles are equal but the third is different (which is 90 degrees in all cases). The other options are incorrect. Option 2 would describe a cubic crystal system. Option 3 is incorrect because while two axial lengths are equal, the third is different. Option 4 is incorrect because only two axial lengths are equal.