Neutralization of Gastric Acid. In the duodenum, gastric acid is neutralized by sodium bicarbonate (pH of about 8.5)
The pH of sodium citrate solutions typically exceeds 7.0, and common antacid, calcium carbonate, is 9.91.
Considering bleach has a pH of about 13 that’s definitely the wrong answer.
7 sounds the most reasonable but 6.5 is not far off.