Instead of saying "I went to the park," $4-$year$-$old Vikram says, "I goed to the park." This error is an example of $\_\_\_\_\_\_\_,$ which suggests that Vikram $\_\_\_\_\_\_\_\_\_\_.$

Question $24$Select one:

a$.$

Overregularization; has learned a grammatical rule

b$.$

Fast mapping; has learned a grammatical rule

c$.$

Overregularization; has not learned a grammatical rule

d$.$

Fast mapping; has not learned a grammatical rule