We need a quality that is similar to wooden (lacking in emotion or energy), and the opposite of personable and thoughtful.

Clearly the options are standoffish and uncongenial.

The opposites of wooden are convivial and blithe (as in carefree and happy).

Candid means honest and sincere and portentous means something that signals a bad or unpleasant happening in the future. Both are irrelevant.

The answers are B and D.