A grand jury was investigating a bank robbery. The only information known to the prosecutor was a rumor that Taylor might have been involved. The grand jury subpoenaed Taylor. He refused to answer questions about the robbery and was granted use immunity. He then testified that he and Simmons had robbed the bank. The grand jury indicted both Taylor and Simmons for the bank robbery. The prosecutor permitted Simmons to enter a plea to a lesser offense in exchange for Simmons' agreement to testify against Taylor. The prosecutor had no evidence as to the identity of the robbers except the testimony of Simmons and Taylor. At Taylor's trial, his objection to Simmons' being permitted to testify should be
sustained, because the prosecutor may not bargain away the rights of one codefendant in a deal with another.  sustained, because Simmons' testimony was acquired as a result of Taylor's grand jury testimony.  overruled, because the police suspected Taylor even before he testified in the grand jury hearing.  overruled, because a witness cannot be precluded from testifying if his testimony is given voluntarily
Question: A grand jury was investigating a bank robbery. The only information known to the prosecutor was a rumor that Taylor might have been involved. The grand jury subpoenaed Taylor. He refused to answer questions about the robbery and was granted use immunity. He then testified that he and Simmons had robbed the bank. The grand jury indicted both Taylor and Simmons for the bank robbery. The prosecutor permitted Simmons to enter a plea to a lesser offense in exchange for Simmons' agreement to testify against Taylor. The prosecutor had no evidence as to the identity of the robbers except the testimony of Simmons and Taylor. At Taylor's trial, his objection to Simmons' being permitted to testify should be
A. sustained, because the prosecutor may not bargain away the rights of one codefendant in a deal with another. 
B. sustained, because Simmons' testimony was acquired as a result of Taylor's grand jury testimony. 
C. overruled, because the police suspected Taylor even before he testified in the grand jury hearing. 
D. overruled, because a witness cannot be precluded from testifying if his testimony is given voluntarily
Answer: