Answer:
Option D, The conclusion is valid because the sanitizer had a better kill rate than the soaps.
Step-by-step explanation:
Sanitizers have alcohol in them as a main constituent which is primarily responsible for killing the bacteria and germs.
The main concept behind the efficient working of sanitizers is that when alcohol with in the sanitizer is rubbed on hand , it neutralizes the functioning of bacteria, viruses and in some cases fungis to an extent of killing 99.9 % of these microbes with in 30 seconds. Mostly all the sanitizers have ethyl alcohol as a main constituent.
Hence, option D is correct