For the Following Sentences, Select the Letter of the Incorrect

Multiple Choice

For the following sentences, select the letter of the incorrect past tense verb in each group. When experts studyed the near-perfect remains, their findings revealed that Lyuba nursed its mother's milk but also swallowed bits of mammoth dung, just as baby elephants do today to build up healthy bacteria in their intestines.

A) studyed
B) revealed
C) nursed
D) swallowed