kill(all)$

van=facebook.com/LearningCalculus$

'(integrate(%e^x,u))="?";

'(integrate(%e^x,u))=integrate(%e^x,u)+C;

'(integrate(%e^x,x))=integrate(%e^x,x)+C;

a:   %e^x+c$
b:   %e^u+c$
c: u*%e^x+c$
d: u*%e^u+c$

'(integrate(''(diff(a,x)),u))=(integrate(diff(a,x),u));
'(integrate(''(diff(b,x)),u))=(integrate(diff(b,x),u));
'(integrate(''(diff(c,x)),u))=(integrate(diff(c,x),u));
'(integrate(''(diff(d,x)),u))=(integrate(diff(d,x),u));