What is a repetitive, almost irresistible action?

What is the most accurate statement about sleep and memory?

a. During sleep, neurons in the hippocampus are silent b. During sleep, more than 100 genes decrease their activity c. "offline" replay that occurs during sleep helps the cortex undergo LTP d. Contrary to what researchers expected, sleep has no measurable effect on memory

According to the textbook, most children spend nearly half of their time in physical education classes standing around, rather than exercising

Indicate whether the statement is true or false