A. The counter RES instruction is used to reset the counter.
The counter RES instruction is used to reset the counter to its initial value or to a specified preset value. It is often used in conjunction with a rung condition that becomes true when a certain event occurs, such as a particular input being activated or a timer reaching its preset value. Option B is incorrect because the counter RES instruction is not given the same reference address as the counter instruction. Option C is incorrect because there is no counter instruction that decrements the count when actuated. Option D is incorrect because option B is incorrect.