Answer: C - Snellen
Explanation: A Snellen eye chart is used to measure visual acuity. This chart was developed in 1862 by a Dutch ophthalmologist Herman Snellen.
This chart uses alphanumeric capitals in its 5 by 5 unit grid. An example of the chart is attached.
The Snellen eye chart helps to determine the clarity of one's distance vision and it also helps to determine the legal visual acuity requirement for a valid driver’s license.
It is traditional for families to clean their houses and the areas surrounding before the start of the new year. The word 'dust' in Chinese is a homophone for 'old', thus cleaning the house is symbolic of driving away the bad luck of the previous year to allow for a new start.
B is correct
Article VII of the Constitution stipulated that nine states had to ratify the Constitution for it to go into effect.