Answer:
The correct answer is letter "A": The synonym/antonym group.
Step-by-step explanation:
Fergus I. M. Craik and Robert S. Lockhart in 1972 proposed the Levels-of-processing effects which try to explain the depth of memory retention according to the information that is provided. As more immersed a piece of information is, it is likely to last longer in the individual's memory.
In the example, the synonym/antonym group will not only have to relate words but also learn about their meanings so the possibility of remembering those words is greater.