Questions

The sentence talks about “drought and food security” which has pestered the region and in addition to that the climate and geography has worsened the matter and forced them to come to isolation. “Relegate and downgrade” are the two words which means to move down to a lower position arethe most suitable word to be filled in the blank. “alleviates” which means to make less severe, will not complete the sentence sensibly. “Transgress” which means “to misbehave or to break the law” which does not fit in the context whatsoever.

The meanings of the given words are as follows:
Histrionic: excessively theatrical or dramatic in character or style
Melodramatic: characteristic of melodrama, especially in being exaggerated or overemotional
Theatrical: exaggerated and excessively dramatic
Conscientious: wishing to do one's work or duty well and thoroughly
Diligent: having or showing care and conscientiousness in one's work or duties
Tenacious: tending to keep a firm hold of something; clinging or adhering closely
Retentive: (of a person's memory) effective in retaining facts and impressions
Thrive: (of a child, animal, or plant) grow or develop well or vigorously
Tussle: a vigorous struggle or scuffle, typically in order to obtain or achieve something
Pertinent: relevant or applicable to a
particular matter; apposite Appropriate: suitable or proper in the circumstances
Therefore, it can be observed that option  i.e. ‘melodramatic, theatrical’ forms a synonym- synonym pair of ‘histrionic’.

Lewis Hamilton of Mercedes won the Hungarian Grand Prix for the 6th time, at the Hungaroring circuit, in Hungary.

This is the 67th career victory for Lewis Hamilton.

Micro processor is a program-controlled device, which fetches the instruction from memory, decodes and executes the instructions. Most Micro Processor are single-chip devices.

It is due to the deficiency of Vitamin A. Retinol which is present in vitamin A. Its deficiency causes night blindness. It is available in carrots. 

The economy of the gilded age was characterized by growth in industry.