Which of the following definitions of linguistic terms are correct?

A. Orthoepy is the study of correct grammar in conformity with established regional patterns.

B. Philology is the study of phonemes and other characteristics of the systems of speech sounds in individual languages.

C. Synchronic study pertains to the study of language at a specific historical point.

D. Diachronic study pertains to historical dimensions of language i.e., linguistic change over the period of time.

E Phonology is the study of language in its cultural and social contexts.

Choose the correct answer from the options given below: