Final answer:
The correct word to fill in the blank for the sentence about the bike rider is 'hesitated' because it directly relates to the described consequence of falling due to hesitation.
Step-by-step explanation:
The correct word to complete the sentence is hesitated. In this sentence, the bike rider was unsure about which path to take, causing him to fall over. 'Hesitated' means to pause or be uncertain before making a decision or taking action.
The sentence you provided requires a word that conveys the idea of the bike rider’s uncertainty or deliberation over choosing a path, which eventually leads to his fall. Among the options given, (A) debated, (B) hesitated, (C) contemplated, and (D) pondered, the word that fits most appropriately is hesitated. This is evident because the second clause of the sentence directly mentions 'his hesitation,' thereby indicating that the rider’s immediate action was one of hesitation. So the completed sentence reads: 'The bike rider hesitated on which path to take and his hesitation caused him to fall over onto the ground.'