Correct option is (a) Lightweight
To explain: loglevel is a lightweight, minimal and convenient JavaScript logging library which provides a reliable and extremely easy-to-use layer over the various console.log() methods that are often available, with none of their downsides. loglevel makes these methods safe to use by gracefully handling the cases where they don’t exist and also lets you filter the output of these, to only show messages at warn level or above.