Concept:Stress in a word means which syllable is pronounced louder or longer. For 'thermometer', the stress falls on the second syllable.
Explanation:The word 'thermometer' has four syllables: ther-mom-e-ter.
The second syllable 'mom' receives the primary stress.
This is shown as ther'mometer, where the apostrophe before 'm' indicates the stressed syllable.
Option A puts stress on the first syllable 'ther'.
Option B puts stress on the second syllable but after 'mo' – that is wrong.
Option D puts stress on the last syllable 'ter'.
Only option C correctly places the stress on 'mom'.
Answer:Option C: ther'mometer