In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.
Q: Question: Of the grasses that the essex skipper eats, which is the longest? Passage:Eggs are laid in strings on the stems of grasses where they remain over the winter. The Essex skipper's favoured foodplant is cock's-foot (Dactylis glomerata), and it rarely uses the small skipper's favoured foodplant Yorkshire fog. Essex skippers' other foods include creeping soft grass (Holcus mollis), couch grass (Elymus repens), timothy-grass (Phleum pratense), meadow foxtail (Alopecurus pratensis), false brome (Brachypodium sylvaticum) and tor-grass (Brachypodium pinnatum). This skipper's caterpillars emerge in the spring and feed until June before forming shelters from leaves tied with silk at the base of the foodplant to pupate. Adults fly from July through August. Like most skippers, they are fairly strictly diurnal, though individuals are very rarely encountered during the night.
 Links: a. Elymus repens b. Diurnality c. Caterpillar d. Holcus lanatus
A: 
a