Recall the concept of hyperconjugation

Hyperconjugation is the delocalization of electrons from a $\sigma$-bond (usually a C–H or C–C bond) into an adjacent empty or partially filled $p$-orbital or a $\pi$-system.

Orbital overlap involved

In the most common description, hyperconjugation involves overlap of:

$\sigma \text{ orbital} \; \text{with} \; p \text{ orbital}$

This is why it is often called $\sigma$-$p$ conjugation or no-bond resonance.

Evaluate the options

• A: $\sigma-\sigma$ → Incorrect. This is just overlap forming a normal sigma bond, not hyperconjugation.
• B: $\sigma-p$ → Correct. This is the characteristic overlap in hyperconjugation.
• C: $p-p$ → Incorrect. This is typical of $\pi$-bond formation or conjugation, not hyperconjugation.
• D: $\pi-\pi$ → Incorrect. This refers to conjugation between pi systems, not hyperconjugation.

Final answer

Therefore, the correct option is:

$\boxed{\text{B: } \sigma-p}$

Comparison with stored correct answer

The stored correct answer is B, which matches the derived answer.