Can't push array item to array data property - Vue Js

I a getting data from the laravel using this response :

$unserialize = unserialize($import->field_names);
return response()->json( $unserialize, 200 ) ;

Now on the Vue JS I can console the response using this :

console.log(response); 

and It's showing the data in array (Check the red arrow mark):

Now, I have a options empty array property like this:

options : []

I want to push object data to this array with a key value and text. This key's value will be that response data single item. So, To do this, I am using this:

response.data.forEach((item, index) => {
    this.options.push({
        value: item,
        text: index
    });
});

but If I console

console.log(this.options);

I can not see the array of object to this options propery. I can see this:

can you tell me why? I want this options should store the item like this:

options: [
    { value: null, text: 'Please select some item' },
    { value: 'a', text: 'This is First option' },
    { value: 'b', text: 'Default Selected Option' },
    { value: 'c', text: 'This is another option' },
    { value: 'd', text: 'This one is disabled', disabled: true },
] 

Update:

Console.log(response);