Please clarify as soon as possible

[kavithashravani]

Recent research has indicated that sustainable weight loss is generally a result not of self-deprivation or adopting
an extreme diet, but a healthy lifestyle that integrates a balanced diet, regular exercise, and a long-term approach.
- self-deprivation or adopting an extreme diet, but
- self-deprivation or the adoption of an extreme diet, but of
- self-deprivation or the adoption of an extreme diet, but
- depriving oneself or adopting an extreme diet, but
- depriving oneself or adopting an extreme diet, but that of

[joehurundas]

I go for B; reason: only option B mimics the correct idiomatic structure.
Not of X, but of Y.
Also, X and Y must be grammatically paralleled.

a result not of self-deprivation, but of a healthy life style

[davetzulin]

here is a less obvious split

self-deprivation is an action noun and can only be parallel to a complex gerund.

self-deprivation or adopting <-- wrong
self deprivation or the adoption of... <--- correct

[krishnan.anju1987]

I go for B. parallelism is correct in it. C uses the and thus is not as acceptable.

[tim]

C uses the same "the" that B does, so you cannot eliminate it for that reason. Parallelism is the big idea here, and B is the only one that is parallel. What's the source of this problem?