The correct answer is B) Timber hitch. The timber hitch is the appropriate hitch to use for securing a spar. This hitch is designed to grip and hold a cylindrical object, such as a spar or a pipe, securely in place. The turns of the hitch wrap around the spar, creating a strong connection that resists slipping. The other answer choices are not suitable for securing a spar. The Blackwall hitch (A) is more commonly used for attaching a line to a ring or eye. The two half hitches (C) are better suited for attaching a line to a post or other vertical object. The stage hitch (D) is typically used for securing a line to a platform or stage.