Explaining a year of low GPA

The adcoms understand that there may be reasons why a particular course or semester during undergrad is not reflective of your academic aptitude. It's always best to provide as much context and information as you can to the adcom, and not to leave them guessing. Given that, I definitely recommend using the optional essay space to share this information. That said, you want to make sure that you're not making excuses (even if they're legitimate!), and instead present the information in a strategic way. Here's a simple framework I suggest using to structure your optional essay:

* Succinctly identify the problem or issue (i.e.: the semester that's an outlier on your transcript) and circumstances that contributed (i.e.: mental health issues, illness in your extended family, etc.- be sure to share what you're comfortable with here, but don't overshare; it shouldn't read like a diary entry).

* Clearly explain the steps that you took- and why you took them- in order to address the issue and the result you achieved (i.e.: maybe you sought out therapy, received additional tutoring, and were able to recover your GPA by the following semester as a result). Show that you're a problem solver and able to manage difficult situations.

* Present "proof points" that show that you are academically prepared for b-school and that you won't be an academic risk (i.e.: take MBA Math online and/or complete additional coursework to demonstrate mastery of the content you struggled with during that semester. That's a great idea in general, to help you get back into "student mode" as well).

Good luck and know that rarely does a final admissions decision come down to any one grade/semester of college.