Help me determine the best response to a Value At Risk (VAR) question. This is in relation to an intro to stats course, we were not directly taught VAR, rather this exercise is under the framework of "probability distribution." To that end, any probability model can use used to calculated the Value at Risk.

"A portfolio manager manages a fund of 10mm Pounds Sterling (GBP). The strategy she runs is expected to deliver an estimated avg. rate of return of 10% over the next year, with an annual standard deviation of 20%. What is the annual 5% VAR for the fund?

A) I first tried simply --> 1.645*20%*10,000,000 GBP. This results in an annual 5% VAR of 3,290,000 GBP

B) I then tried adjusting the calculation for the 10% estimated return (again, we were not directly taught this) --> (10%-1.645*20%) *10,000,000 GBP. This results in an annual 5% VAR of 2,290,000 GBP.

C) Lastly, I used the NORM.INV function in Excel --> =NORM.INV(5%, 10%, 20%) * $10,000,000 GBP. This results in an annual 5% VAR of 2,289,070 GBP.

My question: which one is correct? Are they all technically correct? The last two seem quite close to each other, as they both take into account the estimated 10% return, but I am unsure if that is necessarily what I should be doing? I have seen VAR done in a multitude of ways using simple probability distribution models, which is how I came to the above options.