Questions

A bus is a group of conducting lines that carriers data, address, & control signals.

A bus is two or many wire communication method. A bus which communicate between two active devices, it may transfer address, data etc..

To achieve maximum efficiency and reliability a mode of operation known as symmetric multiprocessing is used. In essence, with SMP any process or threads can be assigned to any processor.

A rotameter is a flow meter that measures volumetric flow of liquids and gases.

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’.