Astronomy current events question: moon and large earthquake correlation?

Astronomy 210L, fall semester 2016
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Nathaniel Scharping, "Can the Moon Make an Earthquake Worse?" (September 12, 2016)
blogs.discovermagazine.com/d-brief/2016/09/12/is-the-moon-making-earthquakes-worse/

Researchers found that gravitational forces from the moon and large earthquakes may have:
(A) a statistical correlation.
(B) a cause-and-effect relationship.
(C) a common source of energy.
(D) remnants of the moon's large impact origin.
(E) started Earth's tectonic plate motion.

Correct answer: (A)

Student responses
Sections 70178, 70186
(A) : 12 students
(B) : 8 students
(C) : 3 students
(D) : 0 students
(E) : 5 students