5 Given that the conditions in binary star systems should make planetary formation nearly impossible, it's not surprising that the existence of planets in such systems has lacked __ explanation. Roman Rafikov and Kedron Silsbee shed light on the subject when they used modeling to determine a complex set of factors that could support planets' development. Which choice completes the text with the most logical and precise word or phrase? A) a discernible B) a straightforward C an inconclusive D) an unbiased

## Step 1<br />The problem is a fill-in-the-blank type question where we need to choose the most logical and precise word or phrase to complete the sentence. The sentence is discussing the lack of explanation for the existence of planets in binary star systems.<br /><br />## Step 2<br />The sentence is discussing the lack of explanation for the existence of planets in binary star systems. The sentence is looking for a word that can describe the type of explanation that has been lacking.<br /><br />## Step 3<br />Looking at the options, we need to choose the word that best fits the context of the sentence. The sentence is discussing the lack of explanation, so we need a word that can describe a type of explanation that is not clear or definite.<br /><br />## Step 4<br />Option A, "a discernible", means something that can be perceived or recognized, which doesn't fit the context of the sentence.<br /><br />## Step 5<br />Option B, "a straightforward", means something that is simple and easy to understand, which also doesn't fit the context of the sentence.<br /><br />## Step 6<br />Option C, "an inconclusive", means something that is not definitive or final, which fits the context of the sentence perfectly.<br /><br />## Step 7<br />Option D, "an unbiased", means something that is not influenced by personal feelings or opinions, which doesn't fit the context of the sentence.