Questions

For “Pay for” means give money to someone for goods received. So, it is the phrasal verb which will make the sentence grammatically correct, as the sentence talks about paying money for buying certain articles. Pay out means the act of receiving money or material gain as a compensation. Pay off means to pay a debt. Pay of has no meaning.

To settle a dispute, one needs to have a sound decision-making ability to be able to judge both the sides. Also, a judge is a free body to decide upon any issue. 'Know' is a verb which means to be aware of through observation, inquiry, or information. 'Tactics' refer to an action or strategy carefully planned to achieve a specific end. A judge doesn't need tactics to make a judgment. 'Discretion' means the freedom to decide what should be done in a particular situation. 'Brains' refer to the intellectual capacity. 'Bias' means inclination or prejudice for or against one person or group, especially in a way considered to be unfair. Hence option 3 is the correct response.