Suppose the web page you are working on contains one file input control with the id sourceText. What should you place in the blank within the following JavaScript code to assign an object with information about the first file chosen by the user to the variable text?
document.getElementById("sourceText").onchange = function() {
_____;
};
a. let text = this.files[0]
b. let text = this.sourceText[0]
c. let text = new FileReader()
d. let text = sourceText.innerHTML
