Directions: The sentence given below is followed by 4 alternatives. Select the one which most logically complements the idea contained in the given sentence.

As in prospecting for gold, a scientist may dig with skill, courage, energy and intelligence just a few feet away from the rich vein-but always unsuccessfully.

As a result, practical minded people are increasingly wary of choosing pure science as a profession.

Consequently, in scientific research, the rewards for industry, perseverance and intelligence are highly uncertain.

This accounts for high degree of frustration.

Scientific research requires an intense combination of dedication and determination.