I received form I-797A when my petition for changing F1 to B1 got aprroved last year. I believed that the bottom portion of form I-797A is my I-94, so I submitted form I-797A with my I-539 for extension of my B1 status. I recently received RFE asking for I-94. I don't understand why they asked for I-94 again. Is the bottom portion of form I-797A not a I-94?