(defun PICK (/ OBJ-PT)
  (while (not OBJ-PT)
    (setq OBJ-PT (entsel "\nSelect an ARC: "))
  )
  (setq OBJ (car OBJ-PT))
)
(defun c:A2C (/ OK)
  (while (not OK)
    (pick)
    (while (/= "ARC" (cdr (assoc 0 (entget OBJ))))
      (prompt "\nObject selected is not an ARC...")
      (pick)
    )
    (setq OK T)
  )
  (setq DATA (entget OBJ))
  (setq CPT (cdr (assoc 10 DATA)))
  (setq RAD (cdr (assoc 40 DATA)))
  (setq LAY (cdr (assoc 8 DATA)))
  (entdel OBJ)
  (entmake
    (list
      (cons 0 "CIRCLE")
      (cons 10 CPT)
      (cons 40 RAD)
      (cons 8 LAY)
    )
  )
  (princ)
)