Explanation
JSON syntax structure: + uses curly braces {} to hold objects and square brackets [] to hold arrays + JSON data is written as key/value pairs + A key/value pair consists of a key (must be a string in double quotation marks ""), followed by a colon :, followed by a value. For example: "name":"John" + Each key must be unique + Values must be of type string, number, object, array, boolean or null + Multiple key/value within an object are separated by commas , JSON can use arrays. Arrays are used to store multiple values in a single variable. For example:
{
"name":"John",
"age":30,
"cars":[ "Ford", "BMW", "Fiat"]
}
In the above example, "cars" is an array which contains three values "Ford", "BMW" and "Fiat".
Note: Although our correct answer above does not have curly braces to hold objects but it is still the best choice here.

The command "Router(config)# ip sla responder udp-connect" configures the router to be the destination of jitter measurements by enabling it to respond to UDP connect operations sent by another Cisco device performing IP SLAs operations, which are used for measuring jitter among other metrics. References := Cisco

Explanation
https://learningnetwork.cisco.com/s/question/0D53i00000Ksyty/tostastns-tottattnt