You are provided with a research question, keyphrases about the question, a description of candidate datasets and dataset options. Read the description of popular datasets provided below and select the ones that can be used to validate the following research question. Use your knowledge of machine learning datasets to make the best judgement.
Your response should be formatted as a `json` array. For instance, for the query "Semi supervised image classification", a sample response might be: ["CIFAR-10", "CIFAR-100"]. Do not include any extra text in the response other than the answer array.

Query: A system that generates image captions.

Keyphrases: image captioning images

Dataset description:
Flickr30k: The Flickr30k dataset contains 31,000 images collected from Flickr, together with 5 reference sentences provided by human annotators.
NeuralNews: NeuralNews is a dataset for machine-generated news detection. It consists of human-generated and machine-generated articles.
STAIR Captions: STAIR Captions is a large-scale dataset containing 820,310 Japanese captions. This dataset can be used for caption generation, multimodal retrieval, and image generation.
nocaps: The nocaps benchmark consists of 166,100 human-generated captions describing 15,100 images from the OpenImages validation and test sets.
COCO: The MS COCO (Microsoft Common Objects in Context) dataset is a large-scale object detection, segmentation, key-point detection, and captioning dataset. The dataset consists of 328K images.

Options:- A: Flickr30k  B: NeuralNews  C: STAIR Captions  D: nocaps  E: COCO
["Flickr30k", "COCO"]