Correct Answer & Explanation
Option B
The word 'DECIPHER' means to convert (a text written in code, or a coded signal) into normal language; succeed in understanding or interpreting something that is difficult or obscure. 'Decode' is the most accurate synonym as it means to convert (a coded message) into intelligible language. The other options suggest making something unclear, confusing, or putting into code, which are antonyms or unrelated.