What Process or Observation Misled Scientists into Believing Initially That

What process or observation misled scientists into believing initially that their life-seeking experiments on the Mars Viking Lander had succeeded in detecting evidence of life on our neighboring planet?

A) reaction of water with unstable chemicals that exist upon the surface of Mars
B) growth of substances when water was added, which later turned out to be crystal growth from inert chemicals
C) motions of microscopic components, looking like those of a life-form, but which were caused by the boiling of water under the artificial sunlight of the experiment
D) extremely high absorptivity of Martian rocks to water, because these rocks mimicked life-forms by absorbing water