according to your study unit when discussing language development, performance refers to?

a.understanding
b.expression
c.syntax
d.grammar
my answer is a

What does "your study unit" have to say?

that childrens mastery of language can be explained by the fact that childrens competence (understanding)of language exceeds their performance of language(expression)and that children make sense of sentences by tuning into the deep structure(grammar)which underlies spoken speech

According to your text, your answer is wrong.

should it be b

Yes.

This same thing happens whenever someone (an older child or an adult) is learning a new language. There is a "silent period" (length of time which varies from person to person, and is somewhat dependent on age), during which the person is doing a lot of listening and not a whole lot of intelligible speaking.

This is a basic tenet of Dr Stephen Krashen's Second Language Acquisition ...

so do you think its d

"performance of language(expression)"

No, Ms Sue already told you b is correct. I was just explaining that this happens with older people, too, not just children.

According to my study unit on language development, "performance" refers to the expression of language. This includes speaking, writing, and gesturing to convey meaning and/or thoughts to others. It is the actual production of language in verbal or nonverbal forms. So, your answer of "b. expression" is correct.