How does the diction of this passage best support the tone?

colonel francis crept back to the map room while the others remained in the canteen. he was scavenging for something quite earnestly, constantly peering over his shoulder.

a. the use of present-tense verbs moves the story forward in real time, creating a hurried tone.
b. the narrator uses words such as "crept" and "scavenging," creating a suspicious tone.
c. the use of long, complex sentences causes readers to slow down, creating a suspenseful tone.
d. the narrator creates contrast by saying "others remained in the canteen," creating a conflicted tone.