The very high voltage needed to create a spark across the spark plug is produced at the a. transformer's primary winding. b. transformer's secondary winding. c. battery. d. breaker points.

b ) transformer's secondary winding.

Explanation:

When we switch on the car , the breaker point is closed sending current through primary winding of a transformer creating magnetic field in it. When the point is  opened again  , current stops in the primary coil ,reducing magnetic field to zero. This creates very high voltage in the secondary winding . 12 volt of car battery is transformed into 30000 volt in secondary coil. This high voltage is carried to spark plug by high tension wire.

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.