Answer:
The answer is: b. a blog entry on your website.
Step-by-step explanation:
The others are formal forms of writing and as such, a formal writing style must be used.
A letter to your senator requires a formal tone. A resume of course requires formal writing. An article for a science magazine is a form of academic writing therefore formal.
A blog post on the other hand, should infuse personality, be light-hearted and engaging. Using a formal tone bores the audience.
A blog is often visited for information, education, entertainment and a whole bunch of reasons. But it is recommended that when writing even informative posts, they should be written in ways the audience will enjoy. This is why formal writing style is not suitable for a blog entry for your website.