1 pm is equal to : 

For the measurement of tiny order lengths, a picometer is utilised. Applications for the picometer are numerous and include quantum chemistry, particle physics, quantum physics, acoustics, etc. Although the femtometre is not the smallest unit of length, it may be viewed or measured with current scientific equipment. A Picometer which is one of the units of length is used to measure a distance that is smaller than a meter. 

1 pm is equal to ${10}^{-12} \text{m}$.

Hence option C is correct.