Which of the following about CSPF is TRUE?

Which of the following about CSPF is TRUE?
A . The tail-end router performs the CSPF calculation for an LS
C . CSPF calculations are always performed on RSVP-TE based LSPs.
D . The head-end router performs the CSPF calculation for an LS
F . Each downstream router performs its own CSPF calculation for an LS

Answer: C