Cambridge author Lois Lowry was at the Book Expo America in New York on Wednesday to promote “Son,’’ the sequel to “The Giver.’’ Lowry told us that actor Jeff Bridges still has film rights to “The Giver,’’ which he optioned so long ago that he intended to have his dad, Lloyd Bridges, star as the title character. Now, the younger Bridges is old enough to play the part himself. Lowry said that she and the “Big Lebowski’’ star have maintained a pleasant relationship over the years. Although when he was in town last year to film “R.I.P.D.’’ with Ryan Reynolds, they didn’t hang out. “He never called,’’ Lowry said with a laugh.