The taste quality of bitterness is _________________________.
 | |
 |
likely to indicate a poisonous substance; |
 |
associated with activity of receptor response to plant alkaloids; |
 |
triggered by the presence of hydrogen ions; |
 |
both alternatives a and b are correct; |
 |
all of the alternatives provided are correct; |
[Review Part 1 of the tutorial] [Review Part 2 (Matching) of the tutorial]