An object is attached to a coiled spring. It is pulled down a distance of 3 inches from its equilibrium position, then released. If the time for one complete oscillation is 7 seconds, find the equation of the simple harmonic motion. a.) s left parenthesis t right parenthesis equals 3 sin open parentheses fraction numerator 2 straight pi over denominator 7 end fraction t close parentheses b.) s left parenthesis t right parenthesis equals short dash 3 sin open parentheses fraction numerator 2 straight pi over denominator 7 end fraction t close parentheses c.) s left parenthesis t right parenthesis equals short dash 3 cos open parentheses fraction numerator 2 straight pi over denominator 7 end fraction t close parentheses d.) s left parenthesis t right parenthesis equals 3 cos open parentheses fraction numerator 2 straight pi over denominator 7 end fraction t close parentheses