In His Research on Bilingual Speakers,Lambert Found That

In his research on bilingual speakers,Lambert found that:

A) bilingual speakers scored at least as well as monolinguals on performance tests.
B) having to learn two vocabularies and grammars put bilingual speakers at a disadvantage on performance tests relative to monolinguals.
C) people who learned a second language as adults showed superior cognitive processing compared to monolinguals matched on other variables.
D) people cannot master the grammar of a second language if they begin to learn it after about age seven.