Questions

A software developer called Satoshi Nakamoto proposed bitcoin, which was an electronic payment system based on mathematical proof. The idea was to produce a currency independent of any central authority, transferable electronically, more or less instantly, with very low transaction fees. Bitcoin’s most important characteristic, and the thing that makes it different to conventional money, is that it is decentralized. Bitcoin is created digitally, by a community of people that anyone canjoin. Bitcoins are ‘mined’, using computing power in a distributed network.This network also processes transactions made with the virtual currency, effectively making bitcoin its own payment network.The bitcoin protocol –the rules that make bitcoin work –say that only 21 million bitcoins can ever be created by miners. However, these coins can be divided into smaller parts (the smallest divisible amount is one hundred millionth of a bitcoin and is called a ‘Satoshi’, after the founder of bitcoin). Bitcoin stores details of every single transaction that ever happened in the network in a huge version of a general ledger, called the blockchain.

he phrase is correct and needs no change. The verb ‘topped’ does not need any preposition after it and the adjective ‘early’ and the noun ‘performance’ needno change

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’.