What Two Atomic Orbitals Overlap to Form the Carbon-Carbon $s p ^ { 3 } - s p ^ { 3 }$

What two atomic orbitals overlap to form the carbon-carbon ? bond in ethyne?

A) $s p ^ { 3 } - s p ^ { 3 }$
B) $p - p$
C) $s p ^ { 2 } - s p ^ { 2 }$
D) $S - S$
E) $s p - s p$