Questions

The meanings of the given words are as follows:
Nefarious: (typically of an action or activity) wicked or criminal
Sloppy: careless and unsystematic; excessively casual
Flurry: a small swirling mass of something, especially snow or leaves, moved by sudden gusts of wind

Unassertive: (of a person) not having or showing a confident and forceful personality

Ignoble: not honourable in character or purpose
Modest: unassuming in the estimation of one's abilities or achievements
Subtle: (especially of a change or distinction) so delicate or precise as to be difficult to analyse or describe
Gregarious: (of a person) fond of company; sociable
Magnanimous: generous or forgiving, especially towards a rival or less powerful person
Iniquitous: grossly unfair and morally wrong
Atrocious: horrifyingly wicked
Therefore, it can be observed that option E i.e.

‘iniquitous, atrocious’ forms a synonym- synonym pair of ‘nefarious’.

The Mahanadi is a major river in East Central India. It drains an area of around 141,600 square kilometres and has a total course of 858 kilometres Mahanadi is also known for the Hirakud Dam. The river flows through the states of Chhattisgarh and Odisha. Mahanadi river in central India, rising in the hills of southeastern Chhattisgarh state. 

A firm maximizes profit by operating where marginal revenue equals marginal cost. They use less of an input in producing more products to increse their profits.