By this time I was in a state of considerable nervous tension, although to my reason there was no adequate cause for my condition. My mind, however, was perfectly
clear. I postulated quite unreservedly that nothing supernatural could happen, and to pass the time I began stringing some rhymes together, Ingoldsby fashion, concerning the original legend of the place.
What is the meaning of the word postulated as it is used in this passage?

A. Claimed
B. Demanded
C. Hoped
D. Proved