Correct Option: B

guess (Verb) : to try and give an answer or make a judgement about something without being sure of all the facts
speculate (Verb) : to form an opinion about something without knowing all the facts; wonder;
conjecture; guess
think (Verb) : to have an idea that something is true or possible or to have a particular
opinion about somebody or something
argue (Verb) : to speak angrily with somebody because you disagree with him
speak (Verb) : to talk