$4.$ Create the following indexes. If it is necessary to name the index in your DBMS$,$ use the indicated name.

a$.$ Create an index named TripIndex$1$ on the TripName field in the Trip table.

b$.$ Create an index named TripIndex$2$ on the Type field in the Trip table.

c$.$ Create an index named TripIndex$3$ on the Type and Season fields in the Trip table and list the seasons

in descending order.

$5.$ Drop the TripIndex$3$ index from the Trip table.

$6.$ Specify the integrity constraint that the distance of any trip must be equal to or greater than $4$

In SQL please