1. . METAPHOR- "Richard DRUMMED his fingers on the arm of the chair waiting for his name to be called." 
2. PERSONIFICATION -“Richard drummed his fingers on the ARM OF THE CHAIR waiting for his name to be called." 
3. ONOMATOPOEIA-“The WHIRRING of the drills increased his anxiety, but he held his head high with a sort of cowardly courage."
4. ALLITERATION- "The whirring of the drills increased his anxiety, but HE HELD HIS HEAD HIGH with a sort of cowardly courage."
5. OXYMORON- "The whirring of the drills increased his anxiety, but he held his head high with a sort of COWARDLY COURAGE”
6. SIMILE- “RICHARD BRUSHED AND FLOSSED HIS TEETH LIKE A CLOCKWORK to avoid the wrath of the dentist’s tools, so the news that he had four cavities certainly took him by surprise."
7. PERSONIFICATION -"Richard brushed and flossed his teeth like clockwork to avoid THE WRATH of the dentist’s tools, so the news that he had four cavities certainly took him by surprise."
        
             
        
        
        
The correct answer would be C<span />
        
             
        
        
        
Answer: B
Explanation:
I don't know much about gerunds and I'm not very good at explaining but a gerund is a form that is derived from a verb but it functions as a noun.