7. Roberta __ a bea utiful collie dog A. walk B walks C walkes D n.da

## Step 1<br />The problem is a fill-in-the-blank question that tests your understanding of subject-verb agreement in English. The subject in this sentence is 'Roberta', which is a singular third person subject.<br />## Step 2<br />According to the rules of English grammar, a singular third person subject requires a singular verb. In this case, the verb is 'walk'. However, the verb needs to be in its third person singular form, which is 'walks'.<br />## Step 3<br />The other options 'walk' and 'walkes' are incorrect because they do not agree with the subject 'Roberta'. The option 'n.da' is not a valid verb form in English.