Questions

have

‘Nominal’ is most appropriate word.

The meanings of the given words are as follows:
Tremulous: shaking or quivering slightly 

Stringent: (of regulations, requirements, or conditions) strict, precise, and exacting

Garrulous: excessively talkative, especially on trivial matters
Quivery: shaking or trembling slightly
Steady: firmly fixed, supported, or balanced; not shaking or moving
Conjunctive: relating to or forming a connection or combination of things
Desist: stop doing something; cease or abstain

Abstain: restrain oneself from doing or enjoying something
Defer: put off (an action or event) to a later time; postpone
Terse: sparing in the use of words; abrupt
Abrupt: sudden and unexpected
Therefore, it can be observed that option B i.e. ‘quivery, steady’ forms a synonym-antonym pair of ‘tremulous’.

Smallest particles of matter are known as quarks and leptons that seem to be the fundamental building blocks. This is too small to measure but bigger than 0. This is ofen consider as fundamental building blocks and something even smaller.