Explanation:

A. taciturn; quite: 'Taciturn' describes her personality (reserved in speech), and 'simple in her looks' describes her appearance. The conjunction 'and' connects these two distinct attributes. The word 'though' signals a contrast with her husband. 'Quite' in this context can be interpreted elliptically to mean 'quite the opposite' or 'quite a character', implying the husband is not taciturn or simple, thereby creating the intended contrast.\nB. plain; flamboyant: While 'plain' fits 'simple in her looks' well and 'flamboyant' provides a strong contrast, the combination 'plain and simple in her looks' might be considered somewhat redundant, as 'plain' and 'simple' are very close in meaning regarding appearance, potentially not describing two distinct attributes as effectively as option A.\nC. garrulous; talkative: 'Garrulous' (excessively talkative) does not describe someone's looks. 'Talkative' is a synonym for 'garrulous', failing to create a contrast with the first blank or within the second clause.\nD. credulous; gullible: 'Credulous' (too ready to believe things) does not describe someone's looks. 'Gullible' is a synonym for 'credulous', failing to create a contrast.