Final answer:
Henry is in a hurry because Claire has locked herself in and he heard a revolver. Marty and Sheldon's health conditions or a wedding are not mentioned as reasons for his rush.
Step-by-step explanation:
Based on the provided reference, the reason why Henry is in such a hurry is because Claire has locked herself in and she has the key.
Additionally, Henry mentions that he heard a revolver, suggesting that there might be a dangerous situation that requires urgent attention.
It is not specified in the reference why Marty or Sheldon are dying, nor that Henry is late to Marty and Samantha's wedding, so options a, b, and c can be ruled out as the cause for Henry's hurry.