In this sentence, we are describing how the woman acted in relation to her health. The correct preposition to use in this context is "for."

Now, let's go through each option and determine which one is correct:

A. without regard to: This option is incorrect because it does not use the correct preposition "for." The phrase should be "without regard for."

B. without regard for: This option is correct. It accurately describes that the woman acted without considering or paying attention to her health.

C. without regard: This option is incorrect because it does not include the preposition "for." The complete phrase should be "without regard for."

D. without regard of: This option is incorrect because it uses the incorrect preposition "of." The correct preposition to use in this context is "for," as in "without regard for."

Therefore, the correct answer is: B. without regard for.