Ambition is subdued by poverty.

Answer: Option C

Modified : make partial or minor changes to (something).
Challenged : used euphemistically to indicate that someone suffers disability in a specified respect.
Sombre : having or conveying a feeling of deep seriousness and sadness.
Diluted : (of a liquid) weakened by the addition of water or another solvent.
Subdued : (of a person or their manner) quiet and rather reflective or depressed.

Synonym of Subdued is Sombre