Question

for years, biologists have experimented with using grime - eating bacteria rather than harsh chemicals to clean artworks, and results have been impressive overall. ______ these bacterial strains - which can metabolize centuries worth of oil, glue, dirt, and other surface impurities without creating harmful byproducts - have proven more effective than traditional chemical cleaning methods.
which choice completes the text with the most logical transition?
choose 1 answer:
a additionally,
b in many cases,
c as a result,
d however,

Explanation:

The first part of the text says the results of using bacteria to clean artworks have been "impressive overall". The second part then gives a more specific positive aspect (the bacteria can metabolize centuries' worth of dirt etc. and are more effective than traditional methods). "In many cases" is a good transition as it shows that in a number of situations (not all, but a significant portion) this more specific positive thing holds true. "Additionally" would just add another point without the sense of being in certain situations. "As a result" implies a cause - effect which isn't the case here. "However" would imply a contrast which there isn't.

Answer:

B. In many cases,