Step 1: Set up the match. Four teaching strategies $(a, b, c, d)$ must be matched to four learning principles $(I, II, III, IV)$. Step 2: Map Tactile strategy. Touch-based learning strengthens understanding through hands-on contact, giving $a \to I$. Step 3: Map Verbal description. Describing in words acts as a substitute when visuals are unavailable, giving $b \to II$. Step 4: Map Group activities. Working in groups builds peer cooperation, giving $c \to III$. Step 5: Map Real objects. Handling real objects gives concrete, experiential learning, giving $d \to IV$. Step 6: Combine the pairs. \[ a\text{-}I,\ b\text{-}II,\ c\text{-}III,\ d\text{-}IV \] Step 7: Select the matching option. This straight one-to-one order is option A. \[ \boxed{\text{A. a-I, b-II, c-III, d-IV}} \]
