Final answer:
The most appropriate word to fill in the blank is 'penitent', which means feeling regretful for doing wrong, fitting the context of the sentence where someone begs for their life.
Step-by-step explanation:
The correct word to fill in the blank for the sentence 'They all appeared very _________, and begged hard for their lives.' is penitent. This word means feeling or showing sorrow and regret for having done wrong; repentant. It fits the context of the sentence because it describes a state of remorse which would lead someone to beg for their lives. The other options, lucrative (producing a great deal of profit), ineffectual (not producing any significant or desired effect), and innate (inborn; natural), do not fit the context.
Based on the given reference, which describes people as generous and willing to share once they feel safe, the word penitent also aligns with the idea that once fear is gone, the inherent goodness and contrition in a person can be seen. This implication further supports the choice of the word 'penitent' over the other options provided.