Trump’s pick to become his plus-one as he marches toward November 5 as the presumptive GOP nominee is purportedly narrowing. The search for former President Donald Trump’s Vice President has been whittled down to three top (and young) lawmakers: Sen. Katie Britt (R-AL), Sen. J.D. Vance (R-OH), and Sen. Marco Rubio (R-FL) are the top choices, according to GOP strategist and conservative blogger Ryan Girdusky. Among the trio, all are more than a decade younger than Trump’s former Vice President Mike Pence (who is 64). Rubio, who is 52, is the oldest of the lot. Vance is 39 and Britt is 42. ALSO …