run_test.js

const regex = /(?:^|\s+)([A-Ea-e][.)]\s+(?:(?!\s+[A-Ea-e][.)]\s+)[\s\S])*)/g;
const text = "A) Statement 1 alone   B) Statement 2 alone   C) Both together   D) Either alone   E) Neither";
const tempOptions = [];
let m2;
while ((m2 = regex.exec(text)) !== null) {
  tempOptions.push({
    text: m2[1].trim(),
    index: m2.index,
    letter: m2[1].charAt(0).toUpperCase()
  });
}
console.log("tempOptions:", tempOptions);

const startIdx = tempOptions.findIndex((o) => o.letter === 'A');
let validOpts = [];
if (startIdx >= 0) {
  let expectedLetterCode = 65;
  for (let k = startIdx; k < tempOptions.length; k++) {
    if (tempOptions[k].letter.charCodeAt(0) === expectedLetterCode) {
      validOpts.push(tempOptions[k]);
      expectedLetterCode++;
    } else {
      break;
    }
  }
}
console.log("validOpts length:", validOpts.length);
if (validOpts.length >= 2) {
  const options = validOpts.map((o) => o.text);
  console.log("options:", options);
}