How do you make the plural form of most singular words that end in f?

a. add s to make them plural

b. change f to v and add es

c. change f to ies

d. add an apostrophe plus s

either online or traditional classroom can work for students. which is better will depend on students and teacher. students may have trouble following a lesson in classroom while they can study at their own pace online. other students may have trouble staying focus on their own in online classes. teachers are more used to classroom teaching but they may also be more worry about their jobs teaching online classes and work harder.

well if u read the book you would know that she meant to