If_u_(t)_=_1_for_t_>=_0_and_u_(t)_=_0_for_t_<_0,_determine_the_Laplace_transform_of_[u_(t)_–_u_(t_–_a)].$#

• A. 1/s(1+e^(-as))
• B. 1/s(1-e^(-as))
• C. 1/s(1+e^as)
• D. 1/s(1-e^as)