Read following passage and answer item that follow.
An earthquake comes like a thief in the night, without warning. It was necessary, therefore, to invent instruments that neither slumbered nor slept. Some devices were quite simple. One, for instance, consisted of rods of various lengths and thicknesses which would stand up on end like ninepins. When a shock came it shook the rigid table upon which these stood. If it were gentle, only the more unstable rods fell. If it were severe, they all fell. Thus the rods by falling and by the direction in which they fell, recorded for the slumbering scientist, the strength of a shock that was too weak to waken him and the direction from which it came.
But, instruments far more delicate than that were needed if any really serious advance was to be made. The ideal to be aimed at was to devise an instrument that could record with a pen on paper the movements, of the ground or of the table, as the quake passed by.
Why was it necessary to invent instruments to observe an earthquake ?

Options

A. Because an earthquake comes like a thief in the night.
B. To make people alert about earthquakes during their conscious as
well as unconscious hours.
C. To prove that we are technically advanced.
D. To experiment with the control of man over nature.