Which type of hole can be bored to reach a wall opening with a new circuit cable on an upper floor?

When considering the best type of hole to bore for a new circuit cable that needs to reach a wall opening on an upper floor, the diagonal approach can prove to be the most effective. Boring a diagonal hole allows for a direct path that can navigate around obstacles and existing structures, making it easier to align with the intended wall opening. This is particularly helpful in scenarios where vertical space is limited or when needing to avoid other installed systems like plumbing or HVAC ducts.

A diagonal approach enables flexibility in angling the hole to reach the desired location efficiently, ensuring that the circuit cable can be installed properly without unnecessary bends or kinks that could affect its performance. The other shape options, while they might have their own applications, typically do not provide the same advantageous route for reaching an upper floor wall opening as effectively as a diagonal hole does.