I have seen some anatomy questions or wrong answer explanations on UWorld about the colic veins, so I think the drainage of all of them are fair game. From those questions, The right colic drains the ascending colon and the middle colic drains the transverse and upper part of descending. Therefore I knew to cross out anything with middle or right colic, because those wouldn't drain the cecum. Next, like the other comment said, we have to know that the cecum is part of the midgut, which is drained by the SMV, which only leaves you with the ileocolic --> superior mesenteric answer choice.
"The ileocolic vein is located within the digestive tract. It receives blood from the appendicular vein, and it drains oxygen-depleted blood from the ileum in the small intestine and the cecum and colon, parts of the large intestine.
From there, this deoxygenated blood flows to the superior mesenteric vein, which joins with the hepatic portal vein."