25 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Re-stack the chord in thirds first. Notes may be written out of order: pile them into thirds to find the root, then read up from there.
Check the fifth to spot diminished and augmented. A perfect 5th means major or minor; a diminished 5th means diminished; an augmented 5th means augmented.
Roman-numeral case and figures carry meaning. Case shows quality (upper = major, lower = minor); figured-bass numbers show which chord tone is in the bass.
Read the explanations even when you're right. Each one reinforces a fact that often returns in a different form on the exam.