Answer Happy

Please explain step by step.
Which of the following is the expression of f(t) as a unit step
function?
-3 -2 -1 Lütfen birini seçin: a.f(t) = 2u(t+3) -u(t+1) f(t) b.f(t) = u(t) + u(t+1) + u(t+3) c.f(t)= u(t+3)+ u(t+1) d.f(t) = 2u(t+3) - u(t+1)-u(t) 2 1 2 Take a screenshot