The correct answer is A. She had to use crutchs for several weeks after breaking her leg.
Explanation:
The word spelling refers to the correct way of writing words, this means the way a word is composed just by certain letters and the order of these letters in the word to be grammatically correct. In the case of plurals, which a modification in the word to express there is more than one element of the same kind, spelling plays an important role as depending on the word and grammatic rules you will add -s or -es at the end of the word, modify the other letters in the word or even use the same word for plural or singular. This plural formation in the case of the word "crutch", which is an object that gives you some support to walk, the plural is formed by adding -es at the end of the word, as according to grammar word ending in -s, -x, -sh or -ch became plural by adding -s. Considering the correct plural form for "crutch" is "crutches" the sentence "She had to use crutchs for several weeks after breaking her leg" has a spelling error as the plural form is missing an "e".
