B ~ You cannot tell if someone was touching your hand
Hope this helps! ^^
When you scrape your original sample onto your agar plate, you cannot see how much single bacteria or where the individual bacteria is on your plate- since it's invisible to the naked eye. But when the bacteria start to multiply, you start to see the individual colonies. (from the single bacteria, it begins to multiply within 20 min. maybe after 1-2 days you'll see a colony, meaning there are millions of bacteria)
for example, if you take a water sample and spray it onto an agar plate, you won't know which parts of the agar plate the bacteria landed on. however, when they start to multiply from a single bacterium, you'll see where each starting bacterium was because now you can see a whole bunch of bacteria. (remember that a colony contains millions of bacteria- which allow it to be visible to the naked eye).
so you count the number of colonies, and that'll tell you how much bacteria you started with. if you look at the size of the colonies, you're only looking at how long you allowed the bacteria to incubate (since from the single bacteria that you started with, it's only multiplying and growing outwards).
Answer
The correct option is B.
Reason
A brief technical explanation for each option is given below.
a. Asthma
It is lower respiratory disorder in which air passage way become narrow and swells, produce extra mucus which make difficulty in breathing, and trigger sneezing, wheezing and shortness of breath.
b. Pleurisy
It is lung disease in while pleura, lining of lung and chest cavity become inflamed due to accumulation of pleural fluid. The fluid is accumulated through the process of pleural effusion which may be transudate or exudate.
c. Pulmonary hypertension
It is a condition in which blood pressure increase in lung arteries. It leads to shortness of breath, swelling of legs and fast heartbeat.
d. COPD
Stand for chronic obstructive pulmonary disorder. It is a progressive lung disorder accompanied with chronic bronchitis, emphysema and non-reversible asthma.
e. Emphysema
In this type of lung disorder the alveoli block due to accumulation of fluid in it, that result into low exchange of gases (oxygen and carbon dioxide).