Final answer:
C is not a holder in due course because the promissory note was not completed according to the issuer's authorization, and the act of filling in an unauthorized amount makes C's acceptance of the note not in good faith.
Step-by-step explanation:
The correct answer is option D. C is not a holder in due course. According to the principles of negotiable instruments, for C to be a holder in due course, the promissory note must have been complete and regular on its face when C acquired it.
However, E only signed a blank paper, which D later filled in with an amount (P100,000) that was not authorized by E. Moreover, D's action of filling in an unauthorized amount could be considered fraudulent. The original intention was to issue a note for P10,000, and since C was aware of this fact when accepting the note as payment, C is not a holder in due course. This consequently affects the liabilities that would be enforced in this scenario.