Directions: Complete the following sentence by using the best option from the given choices so that the sentence makes coherent sense.

He is always courteous but ________.

The word 'but' signals a contrast. The sentence contrasts polite manners with emotional distance. 'Aloof' means distant, reserved, or cool in manner - it properly contrasts with being courteous (polite) while maintaining logical coherence. 'Allusive' means indirect in reference, 'alien' means foreign, 'friendly' would not create a proper contrast.