A) short splice is the correct answer. The short splice is the strongest way to join the ends of two ropes because it creates a seamless, continuous connection between the two ropes. The short splice interweaves the strands of the two ropes, forming a strong and secure bond that is less likely to slip or come undone compared to other knot options like the back splice, carrick bend, or square knot. The other options are less suitable for this purpose. The back splice, carrick bend, and square knot are generally used for different applications and do not provide the same level of strength and security when joining the ends of two ropes.