Three groups of rats acquire a memory on day 1. On day 2, rats in group 1 are given a drug that prevents initial long-term storage while they are actively retrieving the memory. Rats in group 2 receive the drug but do not engage in memory retrieval. Rats in group 3 actively retrieve the memory and are shocked 6 hours later when they are not engaged in retrieval. On day 3, all three groups are assessed. Which group will show the GREATEST impairments in memory

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: