在php下拉列表中设置默认选项，并在提交查询时保留

I have below code which creates drop-down from php. I want to achieve 2 things here. 1. I want to set one of the option to be set default. It may be hard coded or selected from query. 2. When hit button, it should retain selected option. I could retrieve selected option using session data with this: I have below code which creates drop-down from