No, it it not (a).
for the answer.
The site above is a good one for foods. SOME milk is not acidic but apparently most types of milk are slightly scidic. According to the next site, saliva is slightly basic at pH 7.4. We know soft drinks are acidic. Blood has a pH VERY close to 7.3-7.4. See below for links.
(Broken Link Removed)
[Note that all three of these sites APPEAR to be written by the same person or company. They use the same language etc.]
The pH of blood can be found at this site and I know it is correct.http://www.chemistry.wustl.edu/~edudev/LabTutorials/Buffer/Buffer.html
The question appears to allow room for more than one answer. Blood is the only answer that is almost ALWAYS right (unless a person is really sick). Saliva is not acidic in most people but it makes a difference whether one has just eaten or not. Most milk is slightly acidic. Soft drinks are acidic.