Which of the following definitions are correct?

a. Bulla: An elevated, circumscribed lesion filled with turbid fluid (pus)
b. Nodule: Solid, elevated, hard or soft, larger than 1 cm
c. Petechiae: Tiny punctate hemorrhages, 1 to 3 mm, round and discrete, dark red, purple, or brown in color
d. Papule: A hypertrophic scar
e. Vesicle: Also known as a friction blister