Which statement is correct about electron orbitals and energy levels?
Although @orthocresol got this first, and it should be credited to him, I'm posting it as an answer.

In option (B), the statement is incorrect as it refers to $d$ orbitals, which can (according to Pauli's Exclusion Principle) hold 2 electrons each, rather than the $d$ subshell, which can hold 10 electrons, as it has a total of 5 $d$ orbitals which can hold 2 electrons each, and $5*2=10$.

Thus, only option (D) is correct.