According to paragraph 5, which of the following is indicated by studies of the mixture holding the inclusions together? A. Large amounts of this material were formed by condensation or melting in the nebula. B. This material contains more iron and iron sulfide than had previously been thought. C. This material is very similar to the material from which the refractory inclusions are made D. The grains in this material are made from the same elements as chondrules are.