H4 Stamping Dropbox Eligibility

[H4Stamping_Queries]

I entered the US on a H-4 visa that has a validity until Sep 2016. I applied for a COS to F-1 in Sep 2014, but don't have F-1 visa stamped on my passport as I hadn't left US. My spouse had a change of petitioner and I intend to go back on H-4 status based on his new H-1B.

 

1. Will I be eligible for dropbox option at the US Consulate? 

2. Should I answer 'Yes' for the below dropbox eligibility question, since my passport has visa stamped with H4 status valid until Sep 2016? 

    I have a previous U.S. visa in the same class as the visa for which I wish to apply