How to parse following nested json array in android using volley library

[anirudha]

{
"response": [
{
"group": "PCB",
"subject":"Physics"
"questions": [
{
"id": 1,
"question": "question1",
"op1": "option1",
"op2": "option2",
"op3": "option3",
"op4": "option4",
"ans": "correct ans"
},
{
"id": 2,
"question": "question2",
"op1": "option1",
"op2": "option2",
"op3": "option3",
"op4": "option4",
"ans": "correct ans"

},
{
"id": 3,
"question": "question3",
"op1": "option1",
"op2": "option2",
"op3": "option3",
"op4": "option4",
"ans": "correct ans"
}

]
}
]
}