It is possible that news sources often retain the original tense in reported speech to convey the immediacy of their reporting. Consider the following:
Jane: "I want pizza."
Father (who couldn't hear): "What did Jane say?"
Mother: "She said she wants pizza."
While "backshifting" (i.e. "She said she wanted pizza.") would not be incorrect, retaining the original tense is probably more common in this scenario.
Another reason that news sources might retain the speaker's original tense is to preserve the distinction between the speaker's description of a situation that no longer exists and one that does.
"I want the support of House Republicans."
"I wanted the support of House Republicans."
One could backshift the first statement and report both of them as "Obama said that he wanted the support of House Republicans." But there obviously was a difference in meaning.
A third possible reason relates to the first. A large part of news reporting is reported speech. (One source says that 90% of newspaper articles are reported speech.) Backshifting the verbs in every sentence would lead to newspapers written almost entirely in the past tense.
In any event, as pointed out in the comments to your question, it is not incorrect to retain the original tense of the reported speech. If the Secretary said "I have faced many hurdles in my life," it is not incorrect to report this as in your example (b).