Answer:
B. Present
Present Simple
Step-by-step explanation:
Sentences having everyday, always, usually, or showing subject's habits, routines usually use present indefinite (also called present simple or simple present) tense. They use first form of the verb without any helping verbs (in simple/positive sentences)
Since the sentence "they eat together everyday at noon" has first form of the verb without any helping verb and also uses a time indicator (everyday) of present indefinite tense, so option B is correct.
Present participle tense uses is/are/am + -ing form of verb.
Past participle tense uses was/were + -ing form of verb.
Past Tense (or Past indefinite) tense uses second form of the verb.