Bunuel's explanation is clear. Thank you Bunuel.
If I may add, I think the trickiest part of this problem is the " reading comprehension " bit of understanding the question.
In practice mode, to be honest I spent 3 minutes reading and re-reading the question stem to no avail.
To be specific, the part that threw me off was the first sentence " A grocery store bought some mangoes at a rate of 5 for a dollar ". It did not occur to me on my first read that this is a prompt for " COGS of 1 mango is 0.2 USD ".
To benefit the GMATclub community, I would suggest reading Bunuel's explanation and at least my way of studying this for exam, is to build a mental framework should this type of question occur in the GMAT exam.
If we use just plain logic, my framework for the exam is:
Step 1: identify input - process - output -> get COGS (0.2 USD per mango) and ASP (0.333 USD per mango for the first basket and 0.167 USD per mango for the second basket)
Step 2: identify unit profit and/or unit loss for all basket -> (the first basket yields us (0.333 - 0.2 = 0.133 USD per mango; the second basket we lose 0.033 USD per mango)
Step 3: see, we if we sell 4 mangoes from the second basket, it annihilates any profit we make from selling 1 mango from the first basket.
Thus, the answer is A.
Apologies for the simplistic language. At least for my brain, this is digestible. Hope this post is useful.