Which statement is correct when comparing $$leave one out$($LOO$)$ cross validation to k$-$fold $($KF$)$ cross validation when k $<$ n$?$

Question $1$Select one:

a$.$

LOO has higher bias, but lower variance than KF$.$

b$.$

LOO has lower bias, but higher variance than KF$.$

c$.$

LOO has lower bias as well as lower variance than KF$,$ but it is computationally more expensive than KF$.$

d$.$

None of the above answers are correct.