Which of the following are true regarding hydroboration of alkene ?( More than one correct statements . )

Which of the following are true regarding hydroboration of alkene ?(

1.	Which of the following are true regarding hydroboration of alkene ?( More than one correct statements . )
Answer» Reaction proceeds through ionic intermediat and syn`-`addition take place. Reaction proceeds through cyclic INTERMEDIATE TRANSITION state and syn`-` addition takes place. Reagent diborane in ether `(THF)` exists as `:` . Reagent exists in `THF` as BORANE `-THF` COMPLEX. Answer :b.,d.