By the same techniques used for genetically enhancing plants, making them disease- or pest-resistant, researchers have been able to increase the amount of protein in potatoes, sweet potatoes, and tobacco.

• ABy the same techniques used for genetically enhancing plants, making them  
• BWith the same techniques to genetically enhance plants, so that they are  
• CEmploying the same techniques used to genetically enhance plants so that they are  
• DEmploying the same techniques to genetically enhance plants, which makes them  
• EEmploying the same techniques for genetically enhancing plants that make them