As DJluvRocks mentioned, Phoenician would match with discovering the glass making unintentionally. The correct answer to 1st blowing glass should be the Syrians. So it should be -Even I chose "Syrian" -- Learnt to blow glass ..because they were the first to learnt that technique. It was mentioned in 3rd paragraph.
Egyptians - Brought Prisoners
Syrians - Learnt to blow glass
Germans - work affected due to political reasons
Venetians - Were forced to move or relocate
Phoenician - discovering the glass making unintentionally.