With no explanation, label text_A→text_B with either "strengthener" or "weakener".
text_A: Swimmer in a red bathing suit, white cap, and blue goggles emerging from the water The swimmer is practicing his/her breaststroke in preparations for taking their lifeguard exam.
text_B: The swimmer is practicing his/her breaststroke because it exercises a specific group of muscles.
weakener.