Why is chemistry flexible

a. it is biased

b. it cannot be verified

c. it adds new evidence

d. it cannot be reproduced

C, it adds new evidence. Chemistry, 99.99% of the time, can be verified and reproduced if the evidence is correct. Having bias doesn't add flexibility, it adds unnecessary rigidity and sometimes ignorance. When new evidence is introduced to a theory or proposition, it changes, or flexes, people's minds, and eventually after being reproduced many times and verified, changes the fundamental past assumptions about said theory or proposition.