This will be used to test whether or not a user is capable of translating into the destination language. There should be unlocked user levels for each destination as well.
The CAPTCHA consists of a single multiple choice question. The question presents a description in the source language and three possible descriptions in the destination language. Two of the possible descriptions are from random articles, the third is the description from the presented source language description. The user unlocks the language by selecting the correct description.
GET language CAPTCHA endpoint with parameters for source and destination language codes returns something along the lines of
```
{ "id": "some_unique_identifier",
"article": {
...summary response here....
},
"options": [
"Description A",
"Description B",
"Description C"
]
}
```
And then an endpoint where the client would POST something along the lines of
```
{
"id": "some_unique_identifier",
"answer": "Description B"
}
```