get the first (or n'th) element in a jq json parsing

I can get the 1st element in a json inside []

$ echo '[{"a":"x", "b":true}, {"a":"XML", "b":false}]' | jq '.[1]'{"a": "XML","b": false}

But if the json is already disassembled (for instance, after filtering entries using 'select'), how can I choose a single entry and avoid the error seen here?

$ echo '[{"a":"x", "b":true}, {"a":"x", "b":false},{"a":"XML", "b":false}]' | jq '.[] | select( .a == "x")'{"a": "x","b": true}{"a": "x","b": false}$ echo '[{"a":"x", "b":true}, {"a":"x", "b":false},{"a":"XML", "b":false}]' | jq '.[] | select( .a == "x") | .[1]'jq: error (at <stdin>:1): Cannot index object with number