OE
The judgmental mind behind this sentence finds his grandmother’s décor “vulgar,” so the first blank should be a synonym for that. “Tacky” fits the bill. Neither “vitreous” (made from glass) or “grizzled” (having gray hair) can reasonably describe the grandmother’s decoratin scheme. The second blank should be something like appropriate: it wouldn’t be appropriate to tell his grandma what he really thinks. Neither “rancorous” (malevolent) or “doting” (to lavish attention on) fits this meaning. “Discerning,” meaning having or showing good judgment or shrewd, fits perfectly. For the third blank, you need a word that describes being nice to someone in order to get a good birthday present. “Amicable” doesn’t capture the strategy of the idea, but “duplicitous” is way too negative. It means deceitful, which is not really an apt description for the act of refraining from telling your grandma that she has terrible taste. “Tactically,” meaning by way of showing adroit planning, is correct.
Answer: A,D,H